Lighting systems including a plurality of separate lighting units may be used for different purposes. For example, in an LED lighting strip several lighting units, each including an LED, may be arranged spaced from each other but connected to a common electrical power supply.
WO 2014/080337 A2 discloses a load control system with signal-level based control. In an embodiment of a DC grid lighting system, a grid controller comprises a local microcontroller which performs control so as to alter or change DC output voltage as a signal level of the power supply. A dim level (from an off level to a full-power level) is signalled using only the two power connections of the DC grid to a luminaire. A microcontroller in the luminaire controls a current source to influence the amount of current through light emitting elements based on a translation of a measured voltage level at the power supply input into the control command signalled from the grid controller
WO 2009/156900 A1 discloses an illumination system with a plurality of illumination units, each comprising a controller. A central controller gives command signals to the light source units. The system is operated in two operative modes. In a TEACH/LEARN mode the central controller communicates to the controllers of the illumination units data defining color scenarios, and the local controllers store these data into scenario memories. In an EXECUTE mode each local controller operates autonomously to execute the color scenario by reading the scenario data from memory.
WO 2013/054221 A1 discloses a coded lighting system comprising a set of light sources and a remote control. The light sources emit coded light. In order to do so, each light source is associated with a unique identifier. The remote control unit or the arrangement comprises an image sensor which captures images comprising light emitted by at least one of the light sources. By analyzing the captured images, the remote control unit or the arrangement is able to associate light sources affecting a particular region and/or object. The remote control unit or the arrangement is thereby able to transmit a control signal comprising updated light settings to the set of light sources.
In U.S. Pat. No. 9,900,963 B1, an LED controller receives signal modulations from a power line, decodes data based on predetermined modulation characteristics and modifies performance parameters based on operational commands.
US 2012/0313544 A1 discloses LED units arranged in a series configuration with a control unit located at the head of a series which provides both electrical power and control signals down a single wire that allows the LED units to be controlled individually. An LED line driver circuit modulates control data onto the electrical current. In the LED units, an LED controller circuit obtains power from the driver line, stores the power in a supply capacitor and generates the required regulated voltages to power the LED unit. A data signal modulated onto the current is demodulated and decoded to extract a data frame. Commands received in the data frame are executed, driving the LEDs to the specified brightness level.